Beaufort Number
or Force
Wind Speed
Description | Effects Land / Sea |
0
1
2
3
4
5
6
7
8
| mph | km/hr | knots |
|
|
|
|
| <1 | <1 | <1 |
|
|
|
|
|
|
|
|
| |||
| mph | kph | knots |
|
|
|
|
|
|
|
|
| |||
| mph | kph | knots |
|
|
|
|
|
|
|
|
| |||
| mph | kph | knots |
|
|
|
|
|
|
|
|
| |||
| mph | kph | knots |
|
|
|
|
|
|
|
|
| |||
| mph | kph | knots |
|
|
|
|
|
|
|
|
| |||
| mph | kph | knots |
|
|
|
|
|
|
|
|
| |||
| mph | kph | knots |
|
|
|
|
|
|
|
|
| |||
| mph | kph | knots |
|
|
|
|
Calm
Light Air
Light Breeze
Gentle Breeze
Moderate Breeze
Fresh Breeze
Strong Breeze
Moderate or Near Gale
Gale or Fresh Gale
Still, calm air, smoke will rise vertically.
Water is
Rising smoke drifts, wind vane is inactive.
Small ripples appear on water surface.
Leaves rustle, can feel wind on your face, wind vanes begin to move.
Small wavelets develop, crests are glassy.
Leaves and small twigs move, light weight flags extend.
Large wavelets, crests start to break, some whitecaps.
Small branches move, raises dust, leaves and paper.
Small waves develop, becoming longer, whitecaps.
Small trees sway.
White crested wavelets (whitecaps) form, some spray.
Large tree branches move, telephone wires begin to "whistle", umbrellas are difficult to keep under control.
Larger waves form, whitecaps prevalent, spray.
Large trees sway, becoming difficult to walk.
Larger waves develop, white foam from breaking waves begins to be blown.
Twigs and small branches are broken from trees, walking is difficult.
Moderately large waves with blown foam.
13
